Plastic material selection for your next project

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By John Davis | May 18, 2016
Plastics material selection for manufacturing

There are many different types of plastic materials being used in the manufacturing industry and with so many choices out there it can be difficult to select a specific solution. A few of the most common materials include polyethylene (PE), polypropylene (PP), polycarbonate (PC), acrylonitrile butadiene styrene (ABS), and various engineering polymers.

While polyethylene and polypropylene are different resins, both have similar properties within their plastic family because they are buoyant materials and are hydrophobic, meaning they do not absorb water. These two commodity plastics are commonly used within the injection molding industry because they are lower in cost, easy to obtain, come in a wide variety of colors, and are favored for their resistance to many chemical solvents, acids, and bases. The material density allows them to float, which can be an advantage or disadvantage depending on the application. Typically, polyethylene and polypropylene materials are used for small, cheap and lightweight products such as reusable water bottles, containers,  children’s toys, and are commonly found in packaging such as plastic bags and films. These materials are not as hard as other plastics and don’t hold up as well to ultra violet (UV) light exposure. On the other hand, these materials can withstand an impact without shattering because they aren’t brittle like glass.

ABS is another favorite within the injection molding industry and is used widely at Elite Plastics, a division of GM Nameplate. The reason for this is due to the chemical composition of this material and the versatility associated with its physical and chemical properties.  For example, ABS has great impact resistance, toughness, and heat resistance, which makes it a great option for housing and bezels because it can handle some impact without breaking. This material can also be processed with additives to improve UV resistance, gloss, and can be found in a wide variety of colors. The price point for ABS is also reasonable. While ABS is a strong material, it doesn’t stand up against high temperatures or external elements as well as other material options.

Polycarbonate is the top choice for most projects because it is reasonably priced, can infuse UV resistant additives, is a good electrical insulator, and has good fire retardant and heat-resistant properties. While polycarbonate is very popular, it isn’t the best choice for a part that has strict flammability restrictions because the piece can shatter if it gets hot enough. 

Even though Elite Plastics is experienced in working with the plastic materials above, they also excel in manufacturing parts that are required to be made of engineering polymers.  In this case, engineering polymers are injection molding grade plastics that have exceptional toughness, stiffness, chemical resistivity, and highest heat-resistant and flame-retardant properties.  Some common engineering polymers include poly ether ketone (PEEK), polyetherimide (PEI), and polysulfone (PSU).  While these materials may have impressive numbers to back them up, they are very expensive to obtain.